Tape cutter and tape printer including the same

ABSTRACT

A tape cutter including: a cutter for cutting a tape-shaped material; a cutter frame for supporting the cutter in such a condition that the cutter can carry out cutting; a cutter driving mechanism for allowing the cutter to perform cutting from a standby position to a cutting position; a tape pressing member for pressing the tape-shaped material in a cutting direction against a receiving member provided on the cutter frame prior to the cutting by the cutter; a pressing spring disposed between the cutter and the tape pressing member to urge the cutter and the tape pressing member in directions away from each other; and a return spring whose one urging end is hooked to the tape pressing member to return the cutter from the cutting position to the standby position by returning the tape pressing member.

CROSS-REFERENCE

The entire disclosure of Japanese Patent Application No. 2011-224718filed on Oct. 12, 2011, which is hereby incorporated by reference in itsentirety.

BACKGROUND

A tape cutter for cutting a printed portion of a band-shaped printingtape is known (see JP-A-2003-237155).

This type of tape cutter includes a slide cutter which cuts the printingtape, a cutter driving mechanism which allows the slide cutter to carryout cutting, a tape pressing member which presses the printing tapeagainst a receiving member provided on a cutter frame prior to thecutting by the slide cutter, a coil spring disposed between the slidecutter and the tape pressing member to urge the cutter and the tapepressing member in directions away from each other, and a return springwhose one urging end is hooked to the slide cutter to return the slidecutter from a cutting position to a standby position.

Upon the start of the cutting by the slide cutter with the aid of thecutter driving mechanism, the tape pressing member shifts together withthe slide cutter to press the printing tape. In this condition, theslide cutter further shifts while compressing the coil spring, and cutsthe printing tape. After the cut of the printing tape, the return springstarts returning action to shift the slide cutter toward the standbyposition along with expansion of the coil spring. With further shift ofthe sliding cutter, the tape pressing member comes into engagement withthe slide cutter, and returns to an original standby position togetherwith the slide cutter.

According to the known tape cutter having this structure, the cutterdriving mechanism shifts the slide cutter (and the tape pressing member)in the cutting direction while resisting the forces of the return springand the coil spring. In this case, the cutter driving mechanism drivesthe slide cutter to allow the cutting operation by the cutter whileresisting practically two spring forces of the return spring functioningas a tension spring and the coil spring functioning as a compressionspring, the two springs of which are connected in parallel with eachother. Thus, an output torque of a power source (motor) of the cutterdriving mechanism is set large enough to resist the two spring forces ofthe springs connected in parallel with each other and the cuttingresistance produced by the slide cutter. This condition increases thesize of the power source (motor), or requires a rigid power transmissionsystem as well as a complicated gear train.

SUMMARY

An advantage of some aspects of the invention is to provide a tapecutter capable of driving a cutter by a relatively small torque, and atape printer including this tape cutter.

A tape cutter according to an aspect of the invention includes: a cutterwhich cuts a tape-shaped material; a cutter frame which supports thecutter in such a condition that the cutter can carry out cutting; acutter driving mechanism which allows the cutter to perform cutting froma standby position to a cutting position; a tape pressing member whichpresses the tape-shaped material in a cutting direction against areceiving member provided on the cutter frame prior to the cutting bythe cutter; a pressing spring disposed between the cutter and the tapepressing member to urge the cutter and the tape pressing member indirections away from each other; and a return spring whose one urgingend is hooked to the tape pressing member to return the cutter from thecutting position to the standby position by returning the tape pressingmember.

According to this structure, the return spring is attached to the tapepressing member such that the return spring and the pressing spring arejoined in series with each other on the cutter driving mechanism. Thisstructure not only reduces the length (stroke) of the return spring butalso achieves relative decrease in an output torque of the cutterdriving mechanism required in the cutting operation by the cutter. Inthe step of returning the cutter, the pressing spring initially returnsthe cutter, and the return spring finally returns the cutter and thetape pressing member to the standby position. Thus, the returning actiontakes place without producing any problem. The cutter employed in thisstructure may be either a slide cutter or a scissors-type cutter. Thetypes of the return spring and the pressing spring may be arbitrarilyselected.

In this case, it is preferable that the cutter includes a cutter blade,and a cutter holder which holds the cutter blade while supported by thecutter frame in such a condition as to freely slide in the cuttingdirection.

According to this structure, the cutter is constituted by the slidecutter which has a thin cutter blade producing small cutting resistance.Thus, the output torque of the cutter driving mechanism can furtherdecrease. It is preferable that the cutter blade is so constructed as tobe freely attachable to and detachable from the cutter holder (as areplaceable component).

In this case, it is preferable that the tape pressing member issupported by the cutter holder in such a condition as to freely slide inthe cutting direction.

According to this structure, the tape pressing member slides prior tothe cutting of the tape-shaped material by the cutter blade at the startof the cutting, and holds the tape-shaped material between the tapepressing member and the receiving member to fix the tape-shaped materialtherebetween. Thus, the cutting of the tape-shaped material can bestabilized.

A tape printer according to another aspect of the invention includes:the tape cutter according to the above aspect; and a printing unitdisposed on the upstream side in the feed direction of the tape-shapedmaterial with respect to the tape cutter to perform printing on thetape-shaped material.

According to this structure, the output torque of the cutter drivingmechanism included in the tape printer decreases. This advantagecontributes to reduction of the cost and size of the tape printer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like reference numbers reference like elements.

FIG. 1 illustrates the entire perspective view of a tape printeraccording to an embodiment of the invention from which a tape cartridgeis removed.

FIG. 2 is a perspective view illustrating the entire structure of a tapecutting mechanism.

FIG. 3 is a perspective view illustrating the entire structure of thetape cutting mechanism at a standby position.

FIG. 4 is a perspective view illustrating the entire structure of thetape cutting mechanism when a tape pressing member presses a tapereceiving member.

FIG. 5 is a perspective view illustrating the entire structure of thetape cutting mechanism when a cutter blade is located at a cuttingposition.

FIG. 6A is a perspective view of a slide cutter as viewed from theinside.

FIG. 6B is a perspective view of the slide cutter as viewed from theoutside.

FIG. 7 is a perspective view of the slide cutter in a disassembledcondition.

DESCRIPTION OF EXEMPLARY EMBODIMENT

A tape printer according to an embodiment of the invention ishereinafter described with reference to the accompanying drawings. Thistape printer prints desired characters, figures and the like on aprinting tape (tape-shaped material) while drawing the printing tapefrom a tape cartridge containing the printing tape and detachablyattached to the tape printer, and cuts a printed portion of the printingtape into a piece having a predetermined length to produce a label.

FIG. 1 illustrates the external appearance of the tape printer. As canbe seen from the figure, a tape printer 1 includes a device main body 3whose outer casing is constituted by a device case 2, and a tapecartridge C detachably attached to the device main body 3. The tapecartridge C houses a printing tape T as a printing target to which areleased tape is attached, and holds the printing tape T in such acondition that the printing tape T can be drawn from the tape cartridgeC.

A key input unit 5 having various types of input keys 4 is provided onthe front half of the upper surface of the device case 2. A liquidcrystal display 6 for displaying input results and others received fromthe key input unit 5 is provided on the right part of the rear half ofthe upper surface of the device case 2. An opening and closing cover 7is disposed on the left part of the rear half of the upper surface ofthe device case 2. A cartridge attachment portion 8 to which the tapecartridge C is detachably attached is formed inside the opening andclosing cover 7. A printing head 9 is provided on the left part of theinterior of the device case 2. A tape outlet port 10 communicating withthe cartridge attachment portion 8 is formed on the left side of thedevice case 2 as an opening through which a printing tape Ta afterprinting is discharged. A tape cutting mechanism (tape cutting unit) 11which makes reciprocating sliding movement for cutting the printing tapeT is equipped within the device case 2 in the vicinity of the tapeoutlet port 10. The details of the tape cutting mechanism 11 will bedescribed later.

The tape cartridge C contains the printing tape T, an ink ribbon R, anda platen 22 within a cartridge case 21 constituted by upper and lowercases. The printing tape T wound around a tape reel 23, and the inkribbon R wound around a ribbon draw-out reel 24 and a ribbon windingreel 25 are accommodated within the cartridge case 21 in such acondition as to freely rotate. The platen 22 is also accommodated withinthe cartridge case 21 in a position adjacent to a head insertion opening26 in such a condition as to freely rotate. The printing tape T drawnfrom the tape reel 23, and the ink ribbon R drawn from the ribbondraw-out reel 24 travel side by side along the head insertion opening 26while overlapping with each other. Then, the printing tape T isforwarded toward the outside of the cartridge case 21, whereas the inkribbon R is wound around the ribbon winding reel 25. In the area wherethe printing tape T and the ink ribbon R travel side by side, the platen22 and the printing head 9 face to the printing tape T and the inkribbon R sandwiched between the platen 22 and the printing head 9, andcarry out printing thereat. The printing tape Ta produced after printingis discharged to the outside. The tape cartridge C is selected fromplural types of tape cartridges having different tape widths.

The details of the tape cutting mechanism 11 and a tape feed mechanism31 included in the tape printer 1 according to this embodiment are nowexplained with reference to FIG. 2. The tape cutting mechanism 11 andthe tape feed mechanism 31 are driven by a driving motor 41 as a commondriving source. The tape feed mechanism 31 operates by the normalrotation of the driving motor 41, while the tape cutting mechanism 11operates by the reverse rotation of the driving motor 41. Thus, the tapecutting mechanism 11 and the tape feed mechanism 31 are driven by thesingle driving motor 41.

A worm 42 a fixed to a main shaft 41 a of the driving motor 41 engageswith a worm wheel 42 b. The worm wheel 42 b engages with a clutchmechanism 43 (clutch gear mechanism). The normal and reverse rotationalforces of the driving motor 41 are converted into a tape feeding action(including printing operation) and a tape cutting action via a worm andworm wheel 42 (worm 42 a and worm wheel 42 b) and the clutch mechanism43. The figure further shows a pulse disk 44 fixed to the tip of themain shaft 41 a of the driving motor 41. This pulse disk 44 and anot-shown photo-interrupter constitute an encoder.

The tape feed mechanism 31 has the driving motor 41 and a feed geartrain (reduction gear train) 32 including the worm and worm wheel 42 andthe clutch mechanism 43. Two output gears 33 and 34 of the feed geartrain 32 rotatably equipped on the back side of the cartridge attachmentportion 8 rotate a ribbon winding driving shaft 35 and the platen 22.More specifically, in response to the normal rotation of the drivingmotor 41, the clutch mechanism 43 connects with the feed gear train 32,whereby the power of the driving motor 41 is transmitted to the ribbonwinding driving shaft 35 and the platen 22 to rotate these components 35and 22.

Similarly, the tape cutting mechanism 11 has the driving motor 41, adrive gear train (reduction gear train) 12 including the worm and wormwheel 42 and the clutch mechanism 43, a cutting cam 14 fixed coaxiallywith a final gear 13 of the drive gear train 12, and a slide cutter 15which performs cutting by the movement of the cutting cam 14. The tapecutting mechanism 11 further includes a return spring 16 which returnsthe slide cutter 15 to a standby position, and a detection switch 17provided on a circuit board to detect the return of the slide cutter 15to the standby position. Thus, the driving motor 41, the drive geartrain 12, and the cutting cam 14 constitute a cutter driving mechanismwhich allows cutting by the slide cutter 15.

The cutting cam 14 is constituted by a so-called plate cam whose camcurve (profile) is formed by a combination of a substantially spiralreturning portion 14 a, and a linear cutting portion 14 b connectingboth ends of the returning portion 14 a. The returning portion 14 aextends in a spiral shape which makes substantially one round. Thecutting portion 14 b extends substantially in the radial direction.Before the start of the cutting, the cutting portion 14 b engages withan engaging projection 18 of the slide cutter 15.

A tape pressing member 53 is provided in the vicinity of the tape outletport 10 to press the printing tape T against a tape receiving member 52(described later) equipped on a cutter frame 51 for fixation of theprinting tape T. A coil spring (pressing spring) 54 provided between thetape pressing member 53 and the slide cutter 15 urges these components53 and 15 in directions away from each other. The return spring 16provided on the tape pressing member 53 is attached in such a conditionthat one urging end of the return spring 16 is hooked to the tapepressing member 53. The other urging end of the return spring 16 ishooked to the interior of the device case 2.

The cutting operation for cutting the printing tape T performed by thetape cutting mechanism is now explained with reference to FIGS. 3through 5.

In the initial condition shown in FIG. 3, the root of the cuttingportion 14 b of the cutting cam 14 contacts the engaging projection 18of the slide cutter 15. When the cutting cam 14 in this condition startsrotation, the tape pressing member 53 is drawn in the direction from therear toward the front while resisting the spring force of the returnspring 16 to reach a position pressing the tape receiving member 52 (seeFIG. 4). Then, a cutter blade 55 (described later) cuts the printingtape T by draw cut while further resisting the spring force of the coilspring 54 (see FIG. 5).

With further rotation of the cutting cam 14, a contact portion of theengaging projection 18 shifts from the cutting portion 14 b to thespiral returning portion 14 a, whereby the slide cutter 15 slowlyreturns to the standby position by the spring force of the coil spring54 and then the spring force of the return spring 16.

As illustrated in FIGS. 6A and 6B and 7, the slide cutter 15 has thecutter blade 55 which cuts the printing tape T, and a cutter holder 56which holds the cutter blade 55. The slide cutter 15 is attached to thecutter frame 51 via the cutter holder 56 in such a condition as tofreely slide. The tape pressing member 53 is attached to the cutterholder 56 in such a condition as to freely slide while urged by the coilspring 54.

The cutter holder 56 is a one-piece component having an L-shaped holdermain body 57 which holds the cutter blade 55 provided at the tip of theholder main body 57, a holder base 57A connected with the lower end ofthe holder main body 57 to hold the holder main body 57, and theengaging projection 18 projected from the middle of the root of theholder main body 57. According to this structure, the cutter blade 55 isattached to the inside (cartridge attachment portion 8 side) at the tipof the holder main body 57, while the tape pressing member 53 and thecoil spring 54 are attached to the outside (tape outlet port 10 side)thereat. A switch butting portion 58 against which the detection switch17 butts is extended from the tip of the holder main body 57.

A pair of upper and lower holding projections 59 are provided on theinner surface of the tip of the holder main body 57. These holdingprojections 59 project toward the opposite projections to hold thecutter blade 55. The cutter blade 55 is attached to the holder main body57 in such a manner that the cutter blade 55 is inserted between thepair of the holding projections 59 from the cam side. The cutter bladeis constituted by an oblique blade which has a parallelogrammicthin-plate shape inclined at 65 degrees, and attached in such acondition that the blade edge facing to above points to the cam side.

On the other hand, a horizontal pin 60 is provided on the outer surfaceof the tip of the holder main body 57. The horizontal pin 60 located inthe middle of the outer surface projects from the rear surface of theswitch butting portion 58 to hold the coil spring 54. A pair of slideregulating grooves 61 are formed above and below the horizontal pin 60such that the horizontal pin 60 is sandwiched between the slideregulating grooves 61. These slide regulating grooves 61 regulate thesliding position of the tape pressing member 53. Moreover, a pair ofupper and lower sliding projections 62 are provided outside the slideregulating grooves 61. These sliding projections 62 contact the cutterframe 51 and slide there along.

In association with the structure of the cutter holder 56, the tapepressing member 53 has a one-piece structure constituted by a pressingmember main body 71, a tape pressing surface 72 provided on the cam sideof the pressing member main body 71, a spring housing 73 projecting fromthe middle of the pressing member main body 71, a spring receivingportion 74 to which the return spring 16 is hooked, a pair of slideengaging portions 75 provided at the upper and lower ends of thepressing member main body 71, and a pair of upper and lower hookportions 76 extended in the horizontal direction from the pressingmember main body 71 toward the switch butting portion 58.

According to this structure, the pair of the hook portions 76 of thetape pressing member 53 engage with the pair of the slide regulatinggrooves 61 of the holder main body 57 in such a condition as to freelyslide. Also, the pair of the slide engaging portions 75 engage withupper and lower guide grooves (not shown) formed in the cutter frame 51in such a condition as to freely slide. In the condition of theseengagements, a half of the coil spring 54 held by the horizontal pin 60is inserted into the spring housing 73 with a press of the coil spring54 applied against the spring housing 73.

The tape receiving member 52 of the cutter frame 51 faces to the tapepressing member 53 with the printing tape T sandwiched between the tapereceiving member 52 and the tape pressing member 53. When the cutterholder 56 is drawn (advances) by the cutting cam 14, the tape pressingmember 53 (tape pressing surface 72) initially presses the printing tapeT against the tape receiving member 52 prior to the cutting by thecutter blade 55. During further advance of the cutter holder 56, thetape pressing member 53 keeps pressing the printing tape T while slidingrelative to the cutter holder 56 and resisting the spring force of thecoil spring 54 (compressing the coil spring 54). On the other hand, thecutter blade 55 advances and cuts the printing tape T in this condition.

After completion of the cutting of the printing tape T, the cutterholder 56 and the cutter blade 55 start retreating by the spring forceof the coil spring 54. When the cutter holder 56 reaches the final stepof retreat, the pair of the hook portions 76 of the tape pressing member53 come into engagement with the cutter holder 56. Then, the tapepressing member 53 retreats together with the cutter holder 56 by thespring force of the return spring 16 to shift away from the printingtape T after cutting. When the cutter holder 56 reaches the standbyposition (home position), the switch butting portion 58 contacts thedetection switch 17 and turns on the detection switch 17.

According to this embodiment, the return spring 16 of the tape cuttingmechanism 11 is attached to the tape pressing member 53. In this case,the driving stroke of the tape pressing member 53 decreases. Morespecifically, the slide cutter 15 initially returns to the positionengaging with the tape pressing member 53 by the spring force of thecoil spring 54 after cutting of the printing tape T. Then, the tapepressing member 53 returns to the standby position by the spring forceof the return spring 16. This structure not only reduces the drivingstroke of the tape pressing member 53, but also produces the practicaljunction between the coil spring 54 and the return spring 16 in series.Accordingly, the torque necessary for driving the slide cutter 15decreases in the driving motor 41.

According to the embodiment disclosed herein, the tape cutting mechanism11 included in the tape printer 1 is a draw-cut type tape cuttingmechanism. However, a press-cut type tape cutting mechanism may beincorporated in the tape printer in place of the draw-cut type tapecutting mechanism 11.

What is claimed is:
 1. A tape cutter comprising: a cutter for cutting atape-shaped material; a cutter frame for supporting the cutter in such acondition that the cutter can carry out cutting; a cutter drivingmechanism for allowing the cutter to perform cutting from a standbyposition to a cutting position; a tape pressing member for pressing thetape-shaped material in a cutting direction against a receiving memberprovided on the cutter frame prior to the cutting by the cutter; apressing spring disposed between the cutter and the tape pressing memberto urge the cutter and the tape pressing member in directions away fromeach other; and a return spring whose one urging end is hooked to thetape pressing member to return the cutter from the cutting position tothe standby position by returning the tape pressing member.
 2. The tapecutter according to claim 1, wherein the cutter includes a cutter blade,and a cutter holder which holds the cutter blade while supported by thecutter frame in such a condition as to freely slide in the cuttingdirection.
 3. The tape cutter according to claim 2, wherein the tapepressing member is supported by the cutter holder in such a condition asto freely slide in the cutting direction.
 4. A tape printer comprising:the tape cutter according to claim 1; and a printing unit disposed onthe upstream side in the feed direction of the tape-shaped material withrespect to the tape cutter to perform printing on the tape-shapedmaterial.
 5. A tape printer comprising: the tape cutter according toclaim 2; and a printing unit disposed on the upstream side in the feeddirection of the tape-shaped material with respect to the tape cutter toperform printing on the tape-shaped material.
 6. A tape printercomprising: the tape cutter according to claim 3; and a printing unitdisposed on the upstream side in the feed direction of the tape-shapedmaterial with respect to the tape cutter to perform printing on thetape-shaped material.